import sys

print("欢迎使用利润计算器")

while True:
    price = int(input("请输入商品的价格:"))

    sales_price = int(input("请输入商品的售卖价格:"))

    profit = sales_price - price

    if profit > 5 and profit < 20:
        num = int(input("请输入售卖的数量:"))
        total_profit = profit * num
        print("本次订单收益{}".format(total_profit))
        break
    elif profit >= 20:
        print("利润高不可售卖")
    else:
        print("不赚钱，重新给价")




